At an early stage of a DCS migration, the question how to switch or cutover from its current (obsolete) DCS to the new DCS is asked. There are two choices that needs to be considered: a Cold Cutover or a Hot cutover
Cold cutover meaning
A cold cutover is replacing the obsolete DCS (distributed control system) to the new DCS while the process is not running, or “cold”. This way of approach is possible during a periodic outage/shutdown/turnaround.
Low Risk
A cold cutover is seen as a low risk approach because there is no process running. Therefore there is no chance to trip the plant nor create a hazardous situation nor (extra) loss of production.
Easier
A cold cutover is considered as an easier approach. Basically it is ‘just’ installing the system, testing and loop check it. After that, the process can be turned on safely.
No practical training
A negative aspect of this approach is that operators will need to learn the new system ‘cold’.
Hot cutover
A hot cutover is an approach of changing from DCS while the plant is in operation or “hot”. The new system is cutover point by point, loop by loop. This cutover methodology requires meticulous planning and orchestration but brings considerable benefits as we will as this discussion develops. Read more about Hot cutover »
Source: http://emersonexchange365.com/solveandsupport/plandesign/f/419/t/6050
